[PING] gnu_vector.exp: Avoid some more known FAILs

  Ping: https://sourceware.org/ml/gdb-patches/2015-07/msg00564.html

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Subject: [PATCH] gnu_vector.exp: Avoid some more known FAILs

This avoids two more types of FAILs with the gnu_vector test case.

First, for POWER targets newer GCCs emit an ABI note when invoked with
"-mcpu=native".  Then the test case fell back to non-native compile,
producing code for a non-vector ABI.  But that is not supported by GDB.
Thus the compiler note is now suppressed with "-Wno-psabi".

Second, on s390 the test case produced FAILs after falling back to a
non-vector ABI when using "finish" or "return" in a vector-valued
function.  This was due to a long-standing known bug (Bug 8549).  This
case is now detected, and KFAILs are emitted instead.

gdb/testsuite/ChangeLog:

	* gdb.base/gnu_vector.exp: Try compilation with "-mcpu=native
	-Wno-psabi" if "-mcpu=native" fails.  For the tests with "finish"
	and "return" use KFAIL when GDB can not read/write the vector
	return value.
---
 gdb/testsuite/gdb.base/gnu_vector.exp | 57 +++++++++++++++++++++++++++--------
 1 file changed, 44 insertions(+), 13 deletions(-)
  

On 08/11/2015 06:27 PM, Andreas Arnez wrote:
> +gdb_test_multiple "return (int4) \{4, 2, 7, 6\}" $test {
> +    -re "#0 .* main .*$gdb_prompt $" {
> +	if { $ok } {
> +	    pass $test
> +	    gdb_test "continue" "4 2 7 6\r\n.*" "verify vector return value"
> +	}
> +    }
> +    -re "The location .* is unknown.\r\n.* return value .* will be ignored.\r\n" {
> +	kfail "gdb/8549" $test
> +	set ok 0
> +	exp_continue
> +    }
> +    -re "Make add_some_intvecs return now. .y or n. $" {
> +	send_gdb "y\n"
> +	exp_continue
> +    }
> +}

If this fails without matching the first pattern above, then we can
end up with a duplicate test message (kfail + fail).

Maybe do something like this instead:

set test "set vector return value"
set should_kfail 0
set finished 0
gdb_test_multiple "return (int4) \{4, 2, 7, 6\}" $test {
    -re "#0 .* main .*$gdb_prompt $" {
        set finished 1
    }
    -re "The location .* is unknown.\r\n.* return value .* will be ignored.\r\n" {
	set should_kfail 1
	exp_continue
    }
    -re "Make add_some_intvecs return now. .y or n. $" {
	send_gdb "y\n"
	exp_continue
    }
}
if { $finished } {
    if { $should_kfail } {
        kfail "gdb/8549" $test
    } else {
	pass $test
        gdb_test "continue" "4 2 7 6\r\n.*" "verify vector return value"
    }
}

Otherwise LGTM.

Thanks,
Pedro Alves
  

On Wed, Aug 12 2015, Pedro Alves wrote:

> On 08/11/2015 06:27 PM, Andreas Arnez wrote:
>> +gdb_test_multiple "return (int4) \{4, 2, 7, 6\}" $test {
>> +    -re "#0 .* main .*$gdb_prompt $" {
>> +	if { $ok } {
>> +	    pass $test
>> +	    gdb_test "continue" "4 2 7 6\r\n.*" "verify vector return value"
>> +	}
>> +    }
>> +    -re "The location .* is unknown.\r\n.* return value .* will be ignored.\r\n" {
>> +	kfail "gdb/8549" $test
>> +	set ok 0
>> +	exp_continue
>> +    }
>> +    -re "Make add_some_intvecs return now. .y or n. $" {
>> +	send_gdb "y\n"
>> +	exp_continue
>> +    }
>> +}
>
> If this fails without matching the first pattern above, then we can
> end up with a duplicate test message (kfail + fail).

That's true.  Thanks for pointing out.

> Maybe do something like this instead:
>
> set test "set vector return value"
> set should_kfail 0
> set finished 0
> gdb_test_multiple "return (int4) \{4, 2, 7, 6\}" $test {
>     -re "#0 .* main .*$gdb_prompt $" {
>         set finished 1
>     }
>     -re "The location .* is unknown.\r\n.* return value .* will be ignored.\r\n" {
> 	set should_kfail 1
> 	exp_continue
>     }
>     -re "Make add_some_intvecs return now. .y or n. $" {
> 	send_gdb "y\n"
> 	exp_continue
>     }
> }
> if { $finished } {
>     if { $should_kfail } {
>         kfail "gdb/8549" $test
>     } else {
> 	pass $test
>         gdb_test "continue" "4 2 7 6\r\n.*" "verify vector return value"
>     }
> }

Right, that would be an option.  After thinking about this a bit I
slightly prefer to go even one step further, like in the approach below.
In my view, it more clearly separates the steps and is more easily
extensible at the end.  But maybe I've been thinking about this too much
already ;-)

OK with this change?


set test "return from vector-valued function"
set should_kfail 0
gdb_test_multiple "return (int4) \{4, 2, 7, 6\}" $test {
    -re "#0 .* main .*$gdb_prompt $" {
	pass $test
    }
    -re "The location .* is unknown.\r\n.* return value .* will be ignored.\r\n" {
	set should_kfail 1
	exp_continue
    }
    -re "Make add_some_intvecs return now. .y or n. $" {
	send_gdb "y\n"
	exp_continue
    }
}
set test "verify vector return value"
gdb_test_multiple "continue" $test {
    -re "4 2 7 6\r\n.*$gdb_prompt $" {
	pass $test
    }
    -re "10 20 48 72\r\n.*$gdb_prompt $" {
	if { $should_kfail } {
	    kfail "gdb/8549" $test
	} else {
	    fail $test
	}
    }
}
  

On 08/13/2015 04:49 PM, Andreas Arnez wrote:

> Right, that would be an option.  After thinking about this a bit I
> slightly prefer to go even one step further, like in the approach below.
> In my view, it more clearly separates the steps and is more easily
> extensible at the end.  But maybe I've been thinking about this too much
> already ;-)
> 

:-)

> OK with this change?

LGTM.

Thanks,
Pedro Alves